Original Posted By: Marc Davis
Hi everybody.I've built my centersection tank with a flat bottom to maximize thecapacity. I've placed two large sumps with drains on opposite corners, rearleft and front right with the bottom sloping slightly towards them.I've been wondering however, if I should have installed another feed in thefront left corner. The condition I'm worried about is landing with low fuellevel and having to hold left wing down. In this condition it's possiblethat fuel won't get to the other drains. It's' really not a problem addinganother drain and line.I'm probably overthinking this. Watching Piets land all weekend, duringapproach and landing the nose down attitude is really pretty level, and inthis case the rear left sump would catch plenty.All thoughts are appreciated as I'm really rabid about fuel flow problems.ThanksDouwe________________________________________________________________________________
Pietenpol-List: fuel drain locations
Re: Pietenpol-List: fuel drain locations
Original Posted By: "Douwe Blumberg"
If it is easy enough to add another drain line then the peace of mind will be worth the effort.Greg----- Original Message -----
If it is easy enough to add another drain line then the peace of mind will be worth the effort.Greg----- Original Message -----
Pietenpol-List: Corvair hub on Piet. plans
Original Posted By: "Gary Boothe"
Mike;Doesn't look to me like anybody actually answered your question about the differencesbetween the two hubs (Pietenpol and Wynne) for the Corvair conversion,so I'll throw in my two cents' worth and see if I can add anything.I have the Pietenpol drawings and the hub sheets are dated November of 1972. Thematerial indicated for the hub is "aluminum casting". The design pioneeredthe use of a "safety shaft" through the center of the hub into a threaded 3/4"deep bore in the center of the crankshaft end (nose). The safety shaft is calledout to be a 5" long, 1" dia. 4130 or 4140 steel rod, or 1" dia. by .250"wall 4130 steel tube, threaded 18 threads to the inch. The hub is mounted tothe crankshaft flange using standard Chevy 11/32" capscrews, 1" long. This requiresthat the holes in the hub be bored very deep into it and that a long,thinwall socket be used to tighten them. The flange itself has a standard boltpattern and is .438" thick at the prop flange. Overall length is given as 2.875".I say all of this to contrast this hub to the Wynne hub, which is quite a bit beefierbut is obviously an adaptation and improvement on Mr. Pietenpol's hub.It is 3.5" long with a 1.1" thick prop flange, and is machined from 2024 aluminum,but William says it could be made from 6061. William's design uses a safetyshaft that is 6" long because the hub is a bit heavier, longer, and stouter-and the safety shaft threads 1" into the crank nose rather than 3/4" as inthe Pietenpol. The threads are 14 threads per inch (coarser than the Pietenpol).While the Pietenpol hub body is slightly tapered, the Wynne design is straight,again making it beefier. William's preferred method of mounting to thecrank flange is through the use of what William calls "hybrid studs", whichare threaded with the Chevy 11/32" on one end and a more standard 3/8-24 threadon the nut end that holds the hub to the crank flange.Here's what William says about the Pietenpol hub in his manual, of which I havethree different editions dating back more than 10 years: "This method was pioneeredby Bernie [sic] Pietenpol in the early 1960s. Although I know of no failuresof Bernie's way of doing it, my method is a little different and usesdifferent materials, but the concept is the same." He also says, "The Pietenpolmethod is brought up for technical reference only. If you are building anexact replica of Bernie's engine, his son Don is the best source of informationon it. Years ago, a number of cast aluminum hubs were made to Bernie's drawings.Some of these are still floating around for sale. These are light dutyunits suited only to the modest flying done by Pietenpols.".My take-away: make your hub using the Pietenpol or the Wynne drawings, but ALWAYSuse a safety shaft and ALWAYS use at least 6061 aluminum, NOT any cast material.To my non-machinist's eye, the two hubs require about the same amount ofmachine work to produce but the Wynne hub has no tapers to cut and is strongerin some important areas, and is a little less than an inch or so longer. Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________
Mike;Doesn't look to me like anybody actually answered your question about the differencesbetween the two hubs (Pietenpol and Wynne) for the Corvair conversion,so I'll throw in my two cents' worth and see if I can add anything.I have the Pietenpol drawings and the hub sheets are dated November of 1972. Thematerial indicated for the hub is "aluminum casting". The design pioneeredthe use of a "safety shaft" through the center of the hub into a threaded 3/4"deep bore in the center of the crankshaft end (nose). The safety shaft is calledout to be a 5" long, 1" dia. 4130 or 4140 steel rod, or 1" dia. by .250"wall 4130 steel tube, threaded 18 threads to the inch. The hub is mounted tothe crankshaft flange using standard Chevy 11/32" capscrews, 1" long. This requiresthat the holes in the hub be bored very deep into it and that a long,thinwall socket be used to tighten them. The flange itself has a standard boltpattern and is .438" thick at the prop flange. Overall length is given as 2.875".I say all of this to contrast this hub to the Wynne hub, which is quite a bit beefierbut is obviously an adaptation and improvement on Mr. Pietenpol's hub.It is 3.5" long with a 1.1" thick prop flange, and is machined from 2024 aluminum,but William says it could be made from 6061. William's design uses a safetyshaft that is 6" long because the hub is a bit heavier, longer, and stouter-and the safety shaft threads 1" into the crank nose rather than 3/4" as inthe Pietenpol. The threads are 14 threads per inch (coarser than the Pietenpol).While the Pietenpol hub body is slightly tapered, the Wynne design is straight,again making it beefier. William's preferred method of mounting to thecrank flange is through the use of what William calls "hybrid studs", whichare threaded with the Chevy 11/32" on one end and a more standard 3/8-24 threadon the nut end that holds the hub to the crank flange.Here's what William says about the Pietenpol hub in his manual, of which I havethree different editions dating back more than 10 years: "This method was pioneeredby Bernie [sic] Pietenpol in the early 1960s. Although I know of no failuresof Bernie's way of doing it, my method is a little different and usesdifferent materials, but the concept is the same." He also says, "The Pietenpolmethod is brought up for technical reference only. If you are building anexact replica of Bernie's engine, his son Don is the best source of informationon it. Years ago, a number of cast aluminum hubs were made to Bernie's drawings.Some of these are still floating around for sale. These are light dutyunits suited only to the modest flying done by Pietenpols.".My take-away: make your hub using the Pietenpol or the Wynne drawings, but ALWAYSuse a safety shaft and ALWAYS use at least 6061 aluminum, NOT any cast material.To my non-machinist's eye, the two hubs require about the same amount ofmachine work to produce but the Wynne hub has no tapers to cut and is strongerin some important areas, and is a little less than an inch or so longer. Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________